In a perspective of climate change, industrial players are racing up to adopt the best strategies for achieving reduced emissions and carbon footprint. Among those, oil refiners and petrochemical operators are in particular looking for solutions about their largest contributor in that matter: Fired equipment. The reduction of emissions from fired heaters could be achieved at the three levels: pre-combustion, combustion and post-combustion.
At Pre-Combustion Level, the solution of “fuel switch”, mostly meaning Fuel Oil (FO) to Fuel Gas (FG) appears to be beneficial for all the species considered (NOx, CO, SOx, PM and CO2).
- NOx: The switch from FO to FG will reduce the flame temperature and as a result reduce the NOx thermally generated. This switch will also be beneficial since unlike the FO, the FG combustion will not contain organo-nitrogen compounds and chemically-formed NOx will be therefore eradicated.
- CO: as long as all the combustion parameters are set correctly, CO emissions with FG will be much lower than those obtained with FO firing.
- SOx: since all sulfur present in the fuel will be recovered at the outlet, the benefit is related to the generally lower sulfur amount in a refinery FG compared to a FO. When available, prefer switch to natural gas which does not contain any sulfur.
- PM: Such emissions are directly related to the fuel quality. Besides the improvement of the FO quality itself (i.e.; unsaturated hydrocarbons, asphaltenes content and Carbon Conradson Residue) often achieved by blending (carefully taking care of possible detrimental phase separation), switching from FO to FG shows naturally a good impact.
- CO2: The positive impact is even enhanced switching to high hydrogen FG: the higher the H/C ratio, the lower the CO2 emissions. The benefits also concern the fuel efficiency, meaning decreasing the quantity of fuel gas consumed. Benefits could further be enhanced by switching to hydrogen. Mind though the adverse effect on the increased of NOx formation due to higher flame temperature.
Heurtey Petrochem Solutions would be happy to help you define the best strategy for improving environmental performance of your fired equipment. Don’t hesitate to contact us for customized solutions.